BAGHDAD, Oct. 25 -- U.S. military fatalities in Iraq reached the 2,000 mark Tuesday with the reported deaths late last week of two Marines and an Army sergeant in two roadside bombings , according to casualty data kept by the Associated Press and Reuters.

The military in Baghdad announced that two Marines died last Friday when the vehicle in which they were traveling was attacked during combat operations by a roadside bomb in Amariya, about 25 miles west of Baghdad. The victims, whose names were not released, were identified as members of the Regimental Combat Team 8, 2nd Marine Division, II Marine Expeditionary Force.

The third casualty was identified by the Department of Defense in Washington as Staff Sgt. George T. Alexander Jr., 34, of Killeen, Tex. He died on Saturday at Brooke Army Medical Center in San Antonio of injuries sustained on Oct. 17 in Samarra, about 65 miles northwest of the capital, when a roadside bomb exploded near his Bradley Fighting Vehicle. Alexander was assigned to the 1st Battalion, 15th Infantry Regiment, 3rd Brigade, 3rd Infantry Division, Fort Benning, Ga.

The milestone of 2,000 deaths is expected to renew focus on U.S. military operations here. The war began in March 2003 as a campaign to topple Iraqi leader Saddam Hussein and secure his presumed arsenal of weapons of mass destruction, but it soon turned into a battle against insurgent groups. Baghdad fell to U.S. troops on April 9, and Hussein was captured in December 2003, but no significant stockpiles of banned weapons have been found.

On May 1, 2003, President Bush declared en end to major combat in Iraq. Shortly afterward, U.S. troops faced an insurgency that combined Sunni Muslim Arabs fighting to end the U.S. military occupation of Iraq and foreign fighters, particularly from the al Qaeda terrorist network, who have made the country part of their battleground against the United States.

Since Bush's declaration, 1,865 U.S. military personnel have been killed, many in suicide bombings, car bombings and other hostile actions.

About 15,220 U.S. servicemen and women have been wounded, including 8,061 who were able to return to duty in 72 hours.

According to iraqbodycount.org, a group that tracks civilian deaths here, between 26,661 and 30,018 Iraqi civilians have died as a result of the conflict. Other groups put Iraqi civilian casualties much higher.

The U.S. military downplayed the significance of reaching 2,000 fatalities. In a message e-mailed to reporters in Baghdad, military spokesman Lt. Col. Steven A. Boylan called it "an artificial mark on the wall set by individuals or groups with specific agendas and ulterior motives. In some cases, this could be the creating [of] news where none really exists.

"The 2,000th soldier, sailor, airman or Marine that is killed in action is just as important as the first that died and will be as important as the last to die."

In Washington, the U.S. Senate held a moment of silence to honor the 2,000 military fatalities.

"Today we learned our nation has crossed a tragic threshold," said Sen. Richard Durbin (D-Ill.). "The enormity of this loss of 2,000 of our best and bravest breaks America's heart."

In a speech on the Senate floor, Durbin said 357 of those killed "never saw their 21st birthday" and that one in four were members of the National Guard and Reserve. U.S. leaders owe the fallen troops and their families answers and accountability, he said, and "cannot allow our nation to drift into a war without end in Iraq." While this is not the time to "cast blame," Durbin said, "we cannot put off the debate over the best course for the future. . . . We do not honor our fallen soldiers simply by adding to their numbers."

Recent public opinion polls show that Americans increasingly favor an early withdrawal of troops, but soldiers in Iraq said the rising death toll stiffened their resolve and would likely make pulling out more difficult.

"To me, 2,000 of us dying here means we're never getting out," said Sgt. Jari Townsend, 25, of Panama City, Fla., whose 4-64 Armor battalion was manning a checkpoint outside the fortified Green Zone this week. "How could you just say, 'That's it' after that? I hate to say it, but it means this is going to be a permanent duty station, a hardship post, and we better get used to it because we are not leaving anytime soon."

"The number 2,000 means a lot to me -- I mean, two of those were two of my best friends," said Sgt. Brian Zamiska, 27 of Bentleyville, Pa., whose 4-64 Armor unit is based in Baghdad. "But it doesn't mean you pack up and leave. I reenlisted. I'll be in 12 more years. I am sure I will be back over here, and we should be. If we leave too soon, they died in vain. If we get a stable situation first, they died for a good cause."

In Kirkuk, Spec. Jason Comstock, 34, a radio operator for the 1st Battalion, 148th Field Artillery Unit, said, "The American people are going to have to decide what price they're willing to pay."

Asked what would be too high a price, he replied: "I don't think it's fair to the Iraqi people to put a number on it. I realize as Americans we struggle with that. But these people are fighting for their freedom, whether it's from Saddam or from the current insurgency. And the Iraqi people are also paying the same price that American soldiers are paying, I'm sure in much greater numbers. So I'm not sure you can put a number on at what point do we say that's enough. But now, regardless of why we're here, we're here. We've got to be willing to stick it out."

Correspondent Steve Fainaru contributed to this report from Kirkuk. Staff writer William Branigin contributed from Washington.